Scotland could cut its contribution to the British monarchy by more than £1 million if plans for further devolution get the go-ahead, it has been claimed.
The Royal Family could expect an annual cut of between £1 million and £1.5 million if profits from the Crown Estate in Scotland are retained by the Scottish Parliament rather than the UK Parliament in a year's time, a royal source said.
The details emerged as royal accounts released showed the cost of travel increased by almost £1 million during 2014/15 compared with the previous year but overall royal household expenditure remained the same.
But both the Scottish and UK governments said they did not expect devolution to have any negative impact on Scotland's contribution to funding the monarchy.
A UK Treasury spokesman said: "Scottish taxpayers will continue to fund a full and fair share of the sovereign grant. The grant will not be adversely affected by devolution – under the Sovereign Grant Act it cannot be reduced."
A Scottish Government spokesman said: "There would be no change in Scotland's contribution to the Sovereign Grant through general taxation."
A royal aide said negotiations were continuing between Westminster and Holyrood over financing, and said Scotland would continue to make contributions to the British monarchy, even if the profits from crown assets were not returned south of the border.
He said: "I think the proposal, although it's not definite yet, is for the transfer of assets from April 1 2016. So the Crown Estate assets under management, in UK terms, would drop at that point."
He said any drop in funding from Scotland would not have any impact on the number of royal engagements in - or the monarchy's relationship with - Scotland, where the Queen spends much of her summer in Balmoral. Prince Charles is also in Scotland this week, having arrived by royal train.
The royal accounts showed that the largest travel cost was for an eight-day tour of Mexico and Colombia involving the Prince of Wales and Duchess of Cornwall, which came to £446,159.
It was one of 63 trips made by royals costing £10,000 or more in the last financial year - up from 47 the previous year - and at a total cost of £5.1 million to the taxpayer compared with £4.2 million a year earlier.
Figures released by Buckingham Palace show the monarchy cost the taxpayer £35.7 million for the second year running - the equivalent of 56p for each person in the country.
Almost half the £35.7 million annual sovereign grant - the system of finance given from the public purse to support the official duties of the monarchy - was spent on payroll costs, while property maintenance dipped from £13.3 million last year to £11.7 million this year - with a surplus of £2.2 million transferred to reserves to help meet the future cost of work on Buckingham Palace.
Major projects included stripping asbestos from the basement floor ducts in the east wing of Buckingham Palace, at a cost of £300,000, as well as the construction of an aircraft hangar for the Queen's helicopter at RAF Odiham in Hampshire, costing £1.2 million.
Sir Alan Reid, keeper of the Privy Purse, said: "It's been a busy year for the Queen and the royal family and the royal household.
"We have contained expenditure, and that is down to strong financial planning and discipline.
"We've worked hard this year to bear down on costs, to maintain revenue and to ensure that the additional funding in the 2014/15 sovereign grant has been placed in reserve.
"Over the coming years, the maintenance of the Estate and in particular Buckingham Palace, will present a significant financial challenge. We will continue to work closely with the trustees to ensure that the funding for the royal household reflects that challenge."
The accounts showed income was £13.3 million - down £100,000 on the previous year - although there were no "big ticket" events during the last 12 months, the Palace said.
The Crown Estate also released its annual accounts today and figures showed it had another record-breaking year with profits of just over £285 million, up 6.7% on the previous year.
The amount of the Sovereign Grant is derived from 15% of the profits from the multi-billion pound Crown Estate - a portfolio of lands, properties and assets like the entire UK seabed.
The funds are allocated two years in arrears so in the 2016-17 financial year it is expected the grant will be £42.7 million.